2 * collectd - src/barometer.c
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU Lesser General Public License as published by
6 * the Free Software Foundation; only version 2.1 of the License is
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public License
15 * along with this program; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
26 #include "utils_cache.h"
29 #include <linux/i2c-dev.h>
32 #include <sys/ioctl.h>
35 /* ------------ MPL115 defines ------------ */
36 /* I2C address of the MPL115 sensor */
37 #define MPL115_I2C_ADDRESS 0x60
39 /* register addresses */
40 #define MPL115_ADDR_CONV 0x00
41 #define MPL115_ADDR_COEFFS 0x04
44 #define MPL115_NUM_CONV 4
45 #define MPL115_NUM_COEFFS 12
47 /* commands / addresses */
48 #define MPL115_CMD_CONVERT_PRESS 0x10
49 #define MPL115_CMD_CONVERT_TEMP 0x11
50 #define MPL115_CMD_CONVERT_BOTH 0x12
52 #define MPL115_CONVERSION_RETRIES 5
54 /* ------------ MPL3115 defines ------------ */
55 /* MPL3115 I2C address */
56 #define MPL3115_I2C_ADDRESS 0x60
58 /* register addresses (only the interesting ones) */
59 #define MPL3115_REG_STATUS 0x00
60 #define MPL3115_REG_OUT_P_MSB 0x01
61 #define MPL3115_REG_OUT_P_CSB 0x02
62 #define MPL3115_REG_OUT_P_LSB 0x03
63 #define MPL3115_REG_OUT_T_MSB 0x04
64 #define MPL3115_REG_OUT_T_LSB 0x05
65 #define MPL3115_REG_DR_STATUS 0x06
66 #define MPL3115_REG_WHO_AM_I 0x0C
67 #define MPL3115_REG_SYSMOD 0x11
68 #define MPL3115_REG_PT_DATA_CFG 0x13
69 #define MPL3115_REG_BAR_IN_MSB 0x14
70 #define MPL3115_REG_BAR_IN_LSB 0x15
71 #define MPL3115_REG_CTRL_REG1 0x26
72 #define MPL3115_REG_CTRL_REG2 0x27
73 #define MPL3115_REG_CTRL_REG3 0x28
74 #define MPL3115_REG_CTRL_REG4 0x29
75 #define MPL3115_REG_CTRL_REG5 0x2A
76 #define MPL3115_REG_OFF_P 0x2B
77 #define MPL3115_REG_OFF_T 0x2C
78 #define MPL3115_REG_OFF_H 0x2D
80 /* Register values, masks */
81 #define MPL3115_WHO_AM_I_RESP 0xC4
83 #define MPL3115_PT_DATA_DREM 0x04
84 #define MPL3115_PT_DATA_PDEF 0x02
85 #define MPL3115_PT_DATA_TDEF 0x01
87 #define MPL3115_DR_STATUS_TDR 0x02
88 #define MPL3115_DR_STATUS_PDR 0x04
89 #define MPL3115_DR_STATUS_PTDR 0x08
90 #define MPL3115_DR_STATUS_DR \
91 (MPL3115_DR_STATUS_TDR | MPL3115_DR_STATUS_PDR | MPL3115_DR_STATUS_PTDR)
93 #define MPL3115_DR_STATUS_TOW 0x20
94 #define MPL3115_DR_STATUS_POW 0x40
95 #define MPL3115_DR_STATUS_PTOW 0x80
97 #define MPL3115_CTRL_REG1_ALT 0x80
98 #define MPL3115_CTRL_REG1_RAW 0x40
99 #define MPL3115_CTRL_REG1_OST_MASK 0x38
100 #define MPL3115_CTRL_REG1_OST_1 0x00
101 #define MPL3115_CTRL_REG1_OST_2 0x08
102 #define MPL3115_CTRL_REG1_OST_4 0x10
103 #define MPL3115_CTRL_REG1_OST_8 0x18
104 #define MPL3115_CTRL_REG1_OST_16 0x20
105 #define MPL3115_CTRL_REG1_OST_32 0x28
106 #define MPL3115_CTRL_REG1_OST_64 0x30
107 #define MPL3115_CTRL_REG1_OST_128 0x38
108 #define MPL3115_CTRL_REG1_RST 0x04
109 #define MPL3115_CTRL_REG1_OST 0x02
110 #define MPL3115_CTRL_REG1_SBYB 0x01
111 #define MPL3115_CTRL_REG1_SBYB_MASK 0xFE
113 #define MPL3115_NUM_CONV_VALS 5
115 /* ------------ BMP085 defines ------------ */
116 /* I2C address of the BMP085 sensor */
117 #define BMP085_I2C_ADDRESS 0x77
119 /* register addresses */
120 #define BMP085_ADDR_ID_REG 0xD0
121 #define BMP085_ADDR_VERSION 0xD1
123 #define BMP085_ADDR_CONV 0xF6
125 #define BMP085_ADDR_CTRL_REG 0xF4
126 #define BMP085_ADDR_COEFFS 0xAA
129 #define BMP085_NUM_COEFFS 22
131 /* commands, values */
132 #define BMP085_CHIP_ID 0x55
134 #define BMP085_CMD_CONVERT_TEMP 0x2E
136 #define BMP085_CMD_CONVERT_PRESS_0 0x34
137 #define BMP085_CMD_CONVERT_PRESS_1 0x74
138 #define BMP085_CMD_CONVERT_PRESS_2 0xB4
139 #define BMP085_CMD_CONVERT_PRESS_3 0xF4
142 #define BMP085_TIME_CNV_TEMP 4500
144 #define BMP085_TIME_CNV_PRESS_0 4500
145 #define BMP085_TIME_CNV_PRESS_1 7500
146 #define BMP085_TIME_CNV_PRESS_2 13500
147 #define BMP085_TIME_CNV_PRESS_3 25500
149 /* ------------ Normalization ------------ */
150 /* Mean sea level pressure normalization methods */
152 #define MSLP_INTERNATIONAL 1
153 #define MSLP_DEU_WETT 2
155 /** Temperature reference history depth for averaging. See
156 * #get_reference_temperature */
157 #define REF_TEMP_AVG_NUM 5
159 /* ------------------------------------------ */
161 /** Supported sensor types */
169 static const char *config_keys[] = {
172 "PressureOffset", /**< only for MPL3115 */
173 "TemperatureOffset", /**< only for MPL3115 */
176 "TemperatureSensor"};
178 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
180 static char *config_device = NULL; /**< I2C bus device */
181 static int config_oversample = 1; /**< averaging window */
183 static double config_press_offset = 0.0; /**< pressure offset */
184 static double config_temp_offset = 0.0; /**< temperature offset */
186 static double config_altitude = NAN; /**< altitude */
187 static int config_normalize = 0; /**< normalization method */
189 static _Bool configured = 0; /**< the whole plugin config status */
191 static int i2c_bus_fd = -1; /**< I2C bus device FD */
193 static enum Sensor_type sensor_type =
194 Sensor_none; /**< detected/used sensor type */
196 static __s32 mpl3115_oversample = 0; /**< MPL3115 CTRL1 oversample setting */
198 // BMP085 configuration
199 static unsigned bmp085_oversampling; /**< BMP085 oversampling (0-3) */
201 bmp085_timeCnvPress; /**< BMP085 conversion time for pressure in us */
202 static __u8 bmp085_cmdCnvPress; /**< BMP085 pressure conversion command */
204 /* MPL115 conversion coefficients */
205 static double mpl115_coeffA0;
206 static double mpl115_coeffB1;
207 static double mpl115_coeffB2;
208 static double mpl115_coeffC12;
209 static double mpl115_coeffC11;
210 static double mpl115_coeffC22;
212 /* BMP085 conversion coefficients */
213 static short bmp085_AC1;
214 static short bmp085_AC2;
215 static short bmp085_AC3;
216 static unsigned short bmp085_AC4;
217 static unsigned short bmp085_AC5;
218 static unsigned short bmp085_AC6;
219 static short bmp085_B1;
220 static short bmp085_B2;
221 static short bmp085_MB;
222 static short bmp085_MC;
223 static short bmp085_MD;
225 /* ------------------------ averaging ring buffer ------------------------ */
226 /* Used only for MPL115. MPL3115 supports real oversampling in the device so */
227 /* no need for any postprocessing. */
229 static _Bool avg_initialized = 0; /**< already initialized by real values */
231 typedef struct averaging_s {
232 long int *ring_buffer;
233 int ring_buffer_size;
234 long int ring_buffer_sum;
235 int ring_buffer_head;
238 static averaging_t pressure_averaging = {NULL, 0, 0L, 0};
239 static averaging_t temperature_averaging = {NULL, 0, 0L, 0};
242 * Create / allocate averaging buffer
244 * The buffer is initialized with zeros.
246 * @param avg pointer to ring buffer to be allocated
247 * @param size requested buffer size
249 * @return Zero when successful
251 static int averaging_create(averaging_t *avg, int size) {
252 avg->ring_buffer = calloc((size_t)size, sizeof(*avg->ring_buffer));
253 if (avg->ring_buffer == NULL) {
254 ERROR("barometer: averaging_create - ring buffer allocation of size %d "
260 avg->ring_buffer_size = size;
261 avg->ring_buffer_sum = 0L;
262 avg->ring_buffer_head = 0;
268 * Delete / free existing averaging buffer
270 * @param avg pointer to the ring buffer to be deleted
272 static void averaging_delete(averaging_t *avg) {
273 if (avg->ring_buffer != NULL) {
274 free(avg->ring_buffer);
275 avg->ring_buffer = NULL;
277 avg->ring_buffer_size = 0;
278 avg->ring_buffer_sum = 0L;
279 avg->ring_buffer_head = 0;
283 * Add new sample to the averaging buffer
285 * A new averaged value is returned. Note that till the buffer is full
286 * returned value is inaccurate as it is an average of real values and initial
289 * @param avg pointer to the ring buffer
290 * @param sample new sample value
292 * @return Averaged sample value
294 static double averaging_add_sample(averaging_t *avg, long int sample) {
297 avg->ring_buffer_sum += sample - avg->ring_buffer[avg->ring_buffer_head];
298 avg->ring_buffer[avg->ring_buffer_head] = sample;
299 avg->ring_buffer_head = (avg->ring_buffer_head + 1) % avg->ring_buffer_size;
300 result = (double)(avg->ring_buffer_sum) / (double)(avg->ring_buffer_size);
302 DEBUG("barometer: averaging_add_sample - added %ld, result = %lf", sample,
308 /* ------------------------ temperature refference ------------------------ */
311 * Linked list type of temperature sensor references
313 typedef struct temperature_list_s {
314 char *sensor_name; /**< sensor name/reference */
315 size_t num_values; /**< number of values (usually one) */
316 _Bool initialized; /**< sensor already provides data */
317 struct temperature_list_s *next; /**< next in the list */
318 } temperature_list_t;
320 static temperature_list_t *temp_list = NULL;
323 * Add new sensor to the temperature reference list
325 * @param list the list
326 * @param sensor reference name (as provided by the config file)
328 * @return Zero when successful
330 static int temp_list_add(temperature_list_t *list, const char *sensor) {
331 temperature_list_t *new_temp;
333 new_temp = malloc(sizeof(*new_temp));
334 if (new_temp == NULL)
337 new_temp->sensor_name = strdup(sensor);
338 new_temp->initialized = 0;
339 new_temp->num_values = 0;
340 if (new_temp->sensor_name == NULL) {
345 new_temp->next = temp_list;
346 temp_list = new_temp;
351 * Delete the whole temperature reference list
353 * @param list the list to be deleted
355 static void temp_list_delete(temperature_list_t **list) {
356 temperature_list_t *tmp;
358 while (*list != NULL) {
360 (*list) = (*list)->next;
361 free(tmp->sensor_name);
368 * Get reference temperature value
370 * First initially uc_get_rate_by_name is tried. At the startup due to
371 * nondeterministic order the temperature may not be read yet (then it fails and
372 * first measurment gives only absolute air pressure reading which is
373 * acceptable). Once it succedes (should be second measurement at the latest) we
374 * use average of few last readings from uc_get_history_by_name. It may take few
375 * readings to start filling so again we use uc_get_rate_by_name as a fallback.
376 * The idea is to use basic "noise" filtering (history averaging) across all the
377 * values which given sensor provides (up to given depth). Then we get minimum
380 * @param result where the result is stored. When not available NAN is stored.
382 * @return Zero when successful
384 static int get_reference_temperature(double *result) {
385 temperature_list_t *list = temp_list;
387 gauge_t *values = NULL; /**< rate values */
388 size_t values_num = 0; /**< number of rate values */
390 gauge_t values_history[REF_TEMP_AVG_NUM];
392 double avg_sum; /**< Value sum for computing average */
393 int avg_num; /**< Number of values for computing average */
394 double average; /**< Resulting value average */
398 while (list != NULL) {
402 /* First time need to read current rate to learn how many values are
403 there (typically for temperature it would be just one). We do not expect
404 dynamic changing of number of temperarure values in runtime yet (are
405 there any such cases?). */
406 if (!list->initialized) {
407 if (uc_get_rate_by_name(list->sensor_name, &values, &values_num)) {
409 "barometer: get_reference_temperature - rate \"%s\" not found yet",
416 "barometer: get_reference_temperature - initialize \"%s\", %zu vals",
417 list->sensor_name, values_num);
419 list->initialized = 1;
420 list->num_values = values_num;
422 for (size_t i = 0; i < values_num; ++i) {
423 DEBUG("barometer: get_reference_temperature - rate %zu: %lf **", i,
425 if (!isnan(values[i])) {
426 avg_sum += values[i];
434 /* It is OK to get here the first time as well, in the worst case
435 the history will full of NANs. */
436 if (uc_get_history_by_name(list->sensor_name, values_history,
437 REF_TEMP_AVG_NUM, list->num_values)) {
438 ERROR("barometer: get_reference_temperature - history \"%s\" lost",
440 list->initialized = 0;
441 list->num_values = 0;
446 for (size_t i = 0; i < REF_TEMP_AVG_NUM * list->num_values; ++i) {
447 DEBUG("barometer: get_reference_temperature - history %zu: %lf", i,
449 if (!isnan(values_history[i])) {
450 avg_sum += values_history[i];
455 if (avg_num == 0) /* still no history? fallback to current */
457 if (uc_get_rate_by_name(list->sensor_name, &values, &values_num)) {
458 ERROR("barometer: get_reference_temperature - rate \"%s\" lost",
460 list->initialized = 0;
461 list->num_values = 0;
466 for (size_t i = 0; i < values_num; ++i) {
467 DEBUG("barometer: get_reference_temperature - rate last %zu: %lf **", i,
469 if (!isnan(values[i])) {
470 avg_sum += values[i];
479 ERROR("barometer: get_reference_temperature - could not read \"%s\"",
481 list->initialized = 0;
482 list->num_values = 0;
484 average = avg_sum / (double)avg_num;
487 else if (*result > average)
491 } /* while sensor list */
493 if (*result == NAN) {
494 ERROR("barometer: get_reference_temperature - no sensor available (yet?)");
497 DEBUG("barometer: get_reference_temperature - temp is %lf", *result);
501 /* ------------------------ MPL115 access ------------------------ */
504 * Detect presence of a MPL115 pressure sensor.
506 * Unfortunately there seems to be no ID register so we just try to read first
507 * conversion coefficient from device at MPL115 address and hope it is really
508 * MPL115. We should use this check as the last resort (which would be the
510 * case anyway since MPL115 is the least accurate sensor).
511 * As a sideeffect will leave set I2C slave address.
513 * @return 1 if MPL115, 0 otherwise
515 static int MPL115_detect(void) {
518 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL115_I2C_ADDRESS) < 0) {
519 ERROR("barometer: MPL115_detect problem setting i2c slave address to "
521 MPL115_I2C_ADDRESS, STRERRNO);
525 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL115_ADDR_COEFFS);
527 DEBUG("barometer: MPL115_detect - positive detection");
531 DEBUG("barometer: MPL115_detect - negative detection");
536 * Read the MPL115 sensor conversion coefficients.
538 * These are (device specific) constants so we can read them just once.
540 * @return Zero when successful
542 static int MPL115_read_coeffs(void) {
543 uint8_t mpl115_coeffs[MPL115_NUM_COEFFS] = {0};
546 int8_t sia0MSB, sia0LSB, sib1MSB, sib1LSB, sib2MSB, sib2LSB;
547 int8_t sic12MSB, sic12LSB, sic11MSB, sic11LSB, sic22MSB, sic22LSB;
548 int16_t sia0, sib1, sib2, sic12, sic11, sic22;
550 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL115_ADDR_COEFFS,
551 STATIC_ARRAY_SIZE(mpl115_coeffs),
554 ERROR("barometer: MPL115_read_coeffs - problem reading data: %s", STRERRNO);
558 /* Using perhaps less elegant/efficient code, but more readable. */
559 /* a0: 16total 1sign 12int 4fract 0pad */
560 sia0MSB = mpl115_coeffs[0];
561 sia0LSB = mpl115_coeffs[1];
562 sia0 = (int16_t)sia0MSB << 8; /* s16 type, Shift to MSB */
563 sia0 += (int16_t)sia0LSB & 0x00FF; /* Add LSB to 16bit number */
564 mpl115_coeffA0 = (double)(sia0);
565 mpl115_coeffA0 /= 8.0; /* 3 fract bits */
567 /* b1: 16total 1sign 2int 13fract 0pad */
568 sib1MSB = mpl115_coeffs[2];
569 sib1LSB = mpl115_coeffs[3];
570 sib1 = sib1MSB << 8; /* Shift to MSB */
571 sib1 += sib1LSB & 0x00FF; /* Add LSB to 16bit number */
572 mpl115_coeffB1 = (double)(sib1);
573 mpl115_coeffB1 /= 8192.0; /* 13 fract */
575 /* b2: 16total 1sign 1int 14fract 0pad */
576 sib2MSB = mpl115_coeffs[4];
577 sib2LSB = mpl115_coeffs[5];
578 sib2 = sib2MSB << 8; /* Shift to MSB */
579 sib2 += sib2LSB & 0x00FF; /* Add LSB to 16bit number */
580 mpl115_coeffB2 = (double)(sib2);
581 mpl115_coeffB2 /= 16384.0; /* 14 fract */
583 /* c12: 14total 1sign 0int 13fract 9pad */
584 sic12MSB = mpl115_coeffs[6];
585 sic12LSB = mpl115_coeffs[7];
586 sic12 = sic12MSB << 8; /* Shift to MSB only by 8 for MSB */
587 sic12 += sic12LSB & 0x00FF;
588 mpl115_coeffC12 = (double)(sic12);
589 mpl115_coeffC12 /= 4.0; /* 16-14=2 */
590 mpl115_coeffC12 /= 4194304.0; /* 13+9=22 fract */
592 /* c11: 11total 1sign 0int 11fract 11pad */
593 sic11MSB = mpl115_coeffs[8];
594 sic11LSB = mpl115_coeffs[9];
595 sic11 = sic11MSB << 8; /* Shift to MSB only by 8 for MSB */
596 sic11 += sic11LSB & 0x00FF;
597 mpl115_coeffC11 = (double)(sic11);
598 mpl115_coeffC11 /= 32.0; /* 16-11=5 */
599 mpl115_coeffC11 /= 4194304.0; /* 11+11=22 fract */
601 /* c12: 11total 1sign 0int 10fract 15pad */
602 sic22MSB = mpl115_coeffs[10];
603 sic22LSB = mpl115_coeffs[11];
604 sic22 = sic22MSB << 8; /* Shift to MSB only by 8 for MSB */
605 sic22 += sic22LSB & 0x00FF;
606 mpl115_coeffC22 = (double)(sic22);
607 mpl115_coeffC22 /= 32.0; // 16-11=5
608 mpl115_coeffC22 /= 33554432.0; /* 10+15=25 fract */
610 DEBUG("barometer: MPL115_read_coeffs: a0=%lf, b1=%lf, b2=%lf, c12=%lf, "
612 mpl115_coeffA0, mpl115_coeffB1, mpl115_coeffB2, mpl115_coeffC12,
613 mpl115_coeffC11, mpl115_coeffC22);
618 * Convert raw adc values to real data using the sensor coefficients.
620 * @param adc_pressure adc pressure value to be converted
621 * @param adc_temp adc temperature value to be converted
622 * @param pressure computed real pressure
623 * @param temperature computed real temperature
625 static void MPL115_convert_adc_to_real(double adc_pressure, double adc_temp,
626 double *pressure, double *temperature) {
628 Pcomp = mpl115_coeffA0 +
629 (mpl115_coeffB1 + mpl115_coeffC11 * adc_pressure +
630 mpl115_coeffC12 * adc_temp) *
632 (mpl115_coeffB2 + mpl115_coeffC22 * adc_temp) * adc_temp;
634 *pressure = ((1150.0 - 500.0) * Pcomp / 1023.0) + 500.0;
635 *temperature = (472.0 - adc_temp) / 5.35 + 25.0;
636 DEBUG("barometer: MPL115_convert_adc_to_real - got %lf hPa, %lf C", *pressure,
641 * Read sensor averegaed measurements
643 * @param pressure averaged measured pressure
644 * @param temperature averaged measured temperature
646 * @return Zero when successful
648 static int MPL115_read_averaged(double *pressure, double *temperature) {
649 uint8_t mpl115_conv[MPL115_NUM_CONV] = {0};
653 int conv_temperature;
655 double adc_temperature;
660 /* start conversion of both temp and presure */
661 retries = MPL115_CONVERSION_RETRIES;
662 while (retries > 0) {
663 /* write 1 to start conversion */
664 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL115_CMD_CONVERT_BOTH, 0x01);
670 ERROR("barometer: MPL115_read_averaged - requesting conversion: %s, "
671 "will retry at most %d more times",
674 ERROR("barometer: MPL115_read_averaged - requesting conversion: %s, "
675 "too many failed retries",
681 usleep(10000); /* wait 10ms for the conversion */
683 retries = MPL115_CONVERSION_RETRIES;
684 while (retries > 0) {
685 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL115_ADDR_CONV,
686 STATIC_ARRAY_SIZE(mpl115_conv),
693 ERROR("barometer: MPL115_read_averaged - reading conversion: %s, "
694 "will retry at most %d more times",
697 ERROR("barometer: MPL115_read_averaged - reading conversion: %s, "
698 "too many failed retries",
704 conv_pressure = ((mpl115_conv[0] << 8) | mpl115_conv[1]) >> 6;
705 conv_temperature = ((mpl115_conv[2] << 8) | mpl115_conv[3]) >> 6;
706 DEBUG("barometer: MPL115_read_averaged, raw pressure ADC value = %d, "
707 "raw temperature ADC value = %d",
708 conv_pressure, conv_temperature);
710 adc_pressure = averaging_add_sample(&pressure_averaging, conv_pressure);
712 averaging_add_sample(&temperature_averaging, conv_temperature);
714 MPL115_convert_adc_to_real(adc_pressure, adc_temperature, pressure,
717 DEBUG("barometer: MPL115_read_averaged - averaged ADC pressure = %lf / "
718 "temperature = %lf, "
719 "real pressure = %lf hPa / temperature = %lf C",
720 adc_pressure, adc_temperature, *pressure, *temperature);
725 /* ------------------------ MPL3115 access ------------------------ */
728 * Detect presence of a MPL3115 pressure sensor by checking register "WHO AM I"
730 * As a sideeffect will leave set I2C slave address.
732 * @return 1 if MPL3115, 0 otherwise
734 static int MPL3115_detect(void) {
737 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, MPL3115_I2C_ADDRESS) < 0) {
738 ERROR("barometer: MPL3115_detect problem setting i2c slave address to "
740 MPL3115_I2C_ADDRESS, STRERRNO);
744 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_WHO_AM_I);
745 if (res == MPL3115_WHO_AM_I_RESP) {
746 DEBUG("barometer: MPL3115_detect - positive detection");
750 DEBUG("barometer: MPL3115_detect - negative detection");
755 * Adjusts oversampling to values supported by MPL3115
757 * MPL3115 supports only power of 2 in the range 1 to 128.
759 static void MPL3115_adjust_oversampling(void) {
762 if (config_oversample > 100) {
764 mpl3115_oversample = MPL3115_CTRL_REG1_OST_128;
765 } else if (config_oversample > 48) {
767 mpl3115_oversample = MPL3115_CTRL_REG1_OST_64;
768 } else if (config_oversample > 24) {
770 mpl3115_oversample = MPL3115_CTRL_REG1_OST_32;
771 } else if (config_oversample > 12) {
773 mpl3115_oversample = MPL3115_CTRL_REG1_OST_16;
774 } else if (config_oversample > 6) {
776 mpl3115_oversample = MPL3115_CTRL_REG1_OST_8;
777 } else if (config_oversample > 3) {
779 mpl3115_oversample = MPL3115_CTRL_REG1_OST_4;
780 } else if (config_oversample > 1) {
782 mpl3115_oversample = MPL3115_CTRL_REG1_OST_2;
785 mpl3115_oversample = MPL3115_CTRL_REG1_OST_1;
788 DEBUG("barometer: MPL3115_adjust_oversampling - correcting oversampling from "
790 config_oversample, new_val);
791 config_oversample = new_val;
795 * Read sensor averaged measurements
797 * @param pressure averaged measured pressure
798 * @param temperature averaged measured temperature
800 * @return Zero when successful
802 static int MPL3115_read(double *pressure, double *temperature) {
805 __u8 data[MPL3115_NUM_CONV_VALS];
806 long int tmp_value = 0;
808 /* Set Active - activate the device from standby */
809 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1);
811 ERROR("barometer: MPL3115_read - cannot read CTRL_REG1: %s", STRERRNO);
815 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
816 ctrl | MPL3115_CTRL_REG1_SBYB);
818 ERROR("barometer: MPL3115_read - problem activating: %s", STRERRNO);
822 /* base sleep is 5ms x OST */
823 usleep(5000 * config_oversample);
825 /* check the flags/status if ready */
826 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
828 ERROR("barometer: MPL3115_read - cannot read status register: %s",
833 while ((res & MPL3115_DR_STATUS_DR) != MPL3115_DR_STATUS_DR) {
834 /* try some extra sleep... */
837 /* ... and repeat the check. The conversion has to finish sooner or later.
839 res = i2c_smbus_read_byte_data(i2c_bus_fd, MPL3115_REG_STATUS);
841 ERROR("barometer: MPL3115_read - cannot read status register: %s",
847 /* Now read all the data in one block. There is address autoincrement. */
848 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, MPL3115_REG_OUT_P_MSB,
849 MPL3115_NUM_CONV_VALS, data);
851 ERROR("barometer: MPL3115_read - cannot read data registers: %s", STRERRNO);
855 tmp_value = (data[0] << 16) | (data[1] << 8) | data[2];
856 *pressure = ((double)tmp_value) / 4.0 / 16.0 / 100.0;
857 DEBUG("barometer: MPL3115_read - absolute pressure = %lf hPa", *pressure);
859 if (data[3] > 0x7F) {
860 data[3] = ~data[3] + 1;
861 *temperature = data[3];
862 *temperature = -*temperature;
864 *temperature = data[3];
867 *temperature += (double)(data[4]) / 256.0;
868 DEBUG("barometer: MPL3115_read - temperature = %lf C", *temperature);
874 * Initialize MPL3115 for barometeric measurements
876 * @return 0 if successful
878 static int MPL3115_init_sensor(void) {
882 /* Reset the sensor. It will reset immediately without ACKing */
883 /* the transaction, so no error handling here. */
884 i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
885 MPL3115_CTRL_REG1_RST);
887 /* wait some time for the reset to finish */
890 /* now it should be in standby already so we can go and configure it */
892 /* Set temperature offset. */
893 /* result = ADCtemp + offset [C] */
894 offset = (__s8)(config_temp_offset * 16.0);
895 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_T, offset);
897 ERROR("barometer: MPL3115_init_sensor - problem setting temp offset: %s",
902 /* Set pressure offset. */
903 /* result = ADCpress + offset [hPa] */
904 offset = (__s8)(config_press_offset * 100.0 / 4.0);
905 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_OFF_P, offset);
908 "barometer: MPL3115_init_sensor - problem setting pressure offset: %s",
913 /* Enable Data Flags in PT_DATA_CFG - flags on both pressure and temp */
914 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_PT_DATA_CFG,
915 MPL3115_PT_DATA_DREM | MPL3115_PT_DATA_PDEF |
916 MPL3115_PT_DATA_TDEF);
918 ERROR("barometer: MPL3115_init_sensor - problem setting PT_DATA_CFG: %s",
923 /* Set to barometer with an OSR */
924 res = i2c_smbus_write_byte_data(i2c_bus_fd, MPL3115_REG_CTRL_REG1,
927 ERROR("barometer: MPL3115_init_sensor - problem configuring CTRL_REG1: %s",
935 /* ------------------------ BMP085 access ------------------------ */
938 * Detect presence of a BMP085 pressure sensor by checking its ID register
940 * As a sideeffect will leave set I2C slave address.
942 * @return 1 if BMP085, 0 otherwise
944 static int BMP085_detect(void) {
947 if (ioctl(i2c_bus_fd, I2C_SLAVE_FORCE, BMP085_I2C_ADDRESS) < 0) {
948 ERROR("barometer: BMP085_detect - problem setting i2c slave address to "
950 BMP085_I2C_ADDRESS, STRERRNO);
954 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_ID_REG);
955 if (res == BMP085_CHIP_ID) {
956 DEBUG("barometer: BMP085_detect - positive detection");
959 res = i2c_smbus_read_byte_data(i2c_bus_fd, BMP085_ADDR_VERSION);
961 ERROR("barometer: BMP085_detect - problem checking chip version: %s",
965 DEBUG("barometer: BMP085_detect - chip version ML:0x%02X AL:0x%02X",
966 res & 0x0f, (res & 0xf0) >> 4);
970 DEBUG("barometer: BMP085_detect - negative detection");
975 * Adjusts oversampling settings to values supported by BMP085
977 * BMP085 supports only 1,2,4 or 8 samples.
979 static void BMP085_adjust_oversampling(void) {
982 if (config_oversample > 6) /* 8 */
985 bmp085_oversampling = 3;
986 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_3;
987 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_3;
988 } else if (config_oversample > 3) /* 4 */
991 bmp085_oversampling = 2;
992 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_2;
993 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_2;
994 } else if (config_oversample > 1) /* 2 */
997 bmp085_oversampling = 1;
998 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_1;
999 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_1;
1003 bmp085_oversampling = 0;
1004 bmp085_cmdCnvPress = BMP085_CMD_CONVERT_PRESS_0;
1005 bmp085_timeCnvPress = BMP085_TIME_CNV_PRESS_0;
1008 DEBUG("barometer: BMP085_adjust_oversampling - correcting oversampling from "
1010 config_oversample, new_val);
1011 config_oversample = new_val;
1015 * Read the BMP085 sensor conversion coefficients.
1017 * These are (device specific) constants so we can read them just once.
1019 * @return Zero when successful
1021 static int BMP085_read_coeffs(void) {
1023 __u8 coeffs[BMP085_NUM_COEFFS];
1025 res = i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_COEFFS,
1026 BMP085_NUM_COEFFS, coeffs);
1028 ERROR("barometer: BMP085_read_coeffs - problem reading data: %s", STRERRNO);
1032 bmp085_AC1 = ((int16_t)coeffs[0] << 8) | (int16_t)coeffs[1];
1033 bmp085_AC2 = ((int16_t)coeffs[2] << 8) | (int16_t)coeffs[3];
1034 bmp085_AC3 = ((int16_t)coeffs[4] << 8) | (int16_t)coeffs[5];
1035 bmp085_AC4 = ((uint16_t)coeffs[6] << 8) | (uint16_t)coeffs[7];
1036 bmp085_AC5 = ((uint16_t)coeffs[8] << 8) | (uint16_t)coeffs[9];
1037 bmp085_AC6 = ((uint16_t)coeffs[10] << 8) | (uint16_t)coeffs[11];
1038 bmp085_B1 = ((int16_t)coeffs[12] << 8) | (int16_t)coeffs[13];
1039 bmp085_B2 = ((int16_t)coeffs[14] << 8) | (int16_t)coeffs[15];
1040 bmp085_MB = ((int16_t)coeffs[16] << 8) | (int16_t)coeffs[17];
1041 bmp085_MC = ((int16_t)coeffs[18] << 8) | (int16_t)coeffs[19];
1042 bmp085_MD = ((int16_t)coeffs[20] << 8) | (int16_t)coeffs[21];
1044 DEBUG("barometer: BMP085_read_coeffs - AC1=%d, AC2=%d, AC3=%d, AC4=%u,"
1045 " AC5=%u, AC6=%u, B1=%d, B2=%d, MB=%d, MC=%d, MD=%d",
1046 bmp085_AC1, bmp085_AC2, bmp085_AC3, bmp085_AC4, bmp085_AC5, bmp085_AC6,
1047 bmp085_B1, bmp085_B2, bmp085_MB, bmp085_MC, bmp085_MD);
1053 * Convert raw BMP085 adc values to real data using the sensor coefficients.
1055 * @param adc_pressure adc pressure value to be converted
1056 * @param adc_temp adc temperature value to be converted
1057 * @param pressure computed real pressure
1058 * @param temperature computed real temperature
1060 static void BMP085_convert_adc_to_real(long adc_pressure, long adc_temperature,
1061 double *pressure, double *temperature)
1066 unsigned long B4, B7;
1071 /* calculate real temperature */
1072 X1 = ((adc_temperature - bmp085_AC6) * bmp085_AC5) >> 15;
1073 X2 = (bmp085_MC << 11) / (X1 + bmp085_MD);
1078 *temperature = (double)T * 0.1;
1080 /* calculate real pressure */
1081 /* in general X1, X2, X3 are recycled while values of B3, B4, B5, B6 are kept
1086 X1 = ((bmp085_B2 * ((B6 * B6) >> 12)) >> 11);
1087 X2 = (((long)bmp085_AC2 * B6) >> 11);
1089 B3 = (((((long)bmp085_AC1 * 4) + X3) << bmp085_oversampling) + 2) >> 2;
1092 X1 = (((long)bmp085_AC3 * B6) >> 13);
1093 X2 = (bmp085_B1 * ((B6 * B6) >> 12)) >> 16;
1094 X3 = ((X1 + X2) + 2) >> 2;
1095 B4 = ((long)bmp085_AC4 * (unsigned long)(X3 + 32768)) >> 15;
1098 B7 = (unsigned long)(adc_pressure - B3) * (50000 >> bmp085_oversampling);
1099 if (B7 < 0x80000000) {
1104 X1 = (P >> 8) * (P >> 8);
1105 X1 = (X1 * 3038) >> 16;
1106 X2 = ((-7357) * P) >> 16;
1107 P = P + ((X1 + X2 + 3791) >> 4);
1109 *pressure = P / 100.0; // in [hPa]
1110 DEBUG("barometer: BMP085_convert_adc_to_real - got %lf hPa, %lf C", *pressure,
1115 * Read compensated sensor measurements
1117 * @param pressure averaged measured pressure
1118 * @param temperature averaged measured temperature
1120 * @return Zero when successful
1122 static int BMP085_read(double *pressure, double *temperature) {
1127 long adc_temperature;
1129 /* start conversion of temperature */
1130 res = i2c_smbus_write_byte_data(i2c_bus_fd, BMP085_ADDR_CTRL_REG,
1131 BMP085_CMD_CONVERT_TEMP);
1133 ERROR("barometer: BMP085_read - problem requesting temperature conversion: "
1139 usleep(BMP085_TIME_CNV_TEMP); /* wait for the conversion */
1142 i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_CONV, 2, measBuff);
1144 ERROR("barometer: BMP085_read - problem reading temperature data: %s",
1149 adc_temperature = ((unsigned short)measBuff[0] << 8) + measBuff[1];
1152 res = i2c_smbus_write_byte_data(i2c_bus_fd, BMP085_ADDR_CTRL_REG,
1153 bmp085_cmdCnvPress);
1155 ERROR("barometer: BMP085_read - problem requesting pressure conversion: %s",
1160 usleep(bmp085_timeCnvPress); /* wait for the conversion */
1163 i2c_smbus_read_i2c_block_data(i2c_bus_fd, BMP085_ADDR_CONV, 3, measBuff);
1165 ERROR("barometer: BMP085_read - problem reading pressure data: %s",
1170 adc_pressure = (long)((((ulong)measBuff[0] << 16) |
1171 ((ulong)measBuff[1] << 8) | (ulong)measBuff[2]) >>
1172 (8 - bmp085_oversampling));
1174 DEBUG("barometer: BMP085_read - raw pressure ADC value = %ld, "
1175 "raw temperature ADC value = %ld",
1176 adc_pressure, adc_temperature);
1178 BMP085_convert_adc_to_real(adc_pressure, adc_temperature, pressure,
1184 /* ------------------------ Sensor detection ------------------------ */
1186 * Detect presence of a supported sensor.
1188 * As a sideeffect will leave set I2C slave address.
1189 * The detection is done in the order BMP085, MPL3115, MPL115 and stops after
1190 * first sensor beeing found.
1192 * @return detected sensor type
1194 static enum Sensor_type detect_sensor_type(void) {
1195 if (BMP085_detect())
1196 return Sensor_BMP085;
1198 else if (MPL3115_detect())
1199 return Sensor_MPL3115;
1201 else if (MPL115_detect())
1202 return Sensor_MPL115;
1207 /* ------------------------ Common functionality ------------------------ */
1210 * Convert absolute pressure (in hPa) to mean sea level pressure
1212 * Implemented methods are:
1213 * - MSLP_NONE - no converions, returns absolute pressure
1215 * - MSLP_INTERNATIONAL - see
1216 * http://en.wikipedia.org/wiki/Atmospheric_pressure#Altitude_atmospheric_pressure_variation
1217 * Requires #config_altitude
1219 * - MSLP_DEU_WETT - formula as recommended by the Deutsche Wetterdienst. See
1220 * http://de.wikipedia.org/wiki/Barometrische_H%C3%B6henformel#Theorie
1221 * Requires both #config_altitude and temperature reference(s).
1223 * @param abs_pressure absloute pressure to be converted
1225 * @return mean sea level pressure if successful, NAN otherwise
1227 static double abs_to_mean_sea_level_pressure(double abs_pressure) {
1232 if (config_normalize >= MSLP_DEU_WETT) {
1233 result = get_reference_temperature(&temp);
1239 switch (config_normalize) {
1241 mean = abs_pressure;
1244 case MSLP_INTERNATIONAL:
1245 mean = abs_pressure / pow(1.0 - 0.0065 * config_altitude / 288.15,
1246 9.80665 * 0.0289644 / (8.31447 * 0.0065));
1249 case MSLP_DEU_WETT: {
1250 double E; /* humidity */
1253 E = 5.6402 * (-0.0916 + exp(0.06 * temp));
1255 E = 18.2194 * (1.0463 - exp(-0.0666 * temp));
1257 (287.05 * (temp + 273.15 + 0.12 * E + 0.0065 * config_altitude / 2)) *
1259 mean = abs_pressure * exp(x);
1264 "barometer: abs_to_mean_sea_level_pressure: wrong conversion method %d",
1266 mean = abs_pressure;
1270 DEBUG("barometer: abs_to_mean_sea_level_pressure: absPressure = %lf hPa, "
1271 "method = %d, meanPressure = %lf hPa",
1272 abs_pressure, config_normalize, mean);
1277 /* ------------------------ main plugin callbacks ------------------------ */
1280 * Main plugin configuration callback (using simple config)
1282 * @param key configuration key we should process
1283 * @param value configuration value we should process
1285 * @return Zero when successful.
1287 static int collectd_barometer_config(const char *key, const char *value) {
1288 DEBUG("barometer: collectd_barometer_config");
1290 if (strcasecmp(key, "Device") == 0) {
1291 sfree(config_device);
1292 config_device = strdup(value);
1293 } else if (strcasecmp(key, "Oversampling") == 0) {
1294 int oversampling_tmp = atoi(value);
1295 if (oversampling_tmp < 1 || oversampling_tmp > 1024) {
1296 WARNING("barometer: collectd_barometer_config: invalid oversampling: %d."
1297 " Allowed values are 1 to 1024 (for MPL115) or 1 to 128 (for "
1298 "MPL3115) or 1 to 8 (for BMP085).",
1302 config_oversample = oversampling_tmp;
1303 } else if (strcasecmp(key, "Altitude") == 0) {
1304 config_altitude = atof(value);
1305 } else if (strcasecmp(key, "Normalization") == 0) {
1306 int normalize_tmp = atoi(value);
1307 if (normalize_tmp < 0 || normalize_tmp > 2) {
1308 WARNING("barometer: collectd_barometer_config: invalid normalization: %d",
1312 config_normalize = normalize_tmp;
1313 } else if (strcasecmp(key, "TemperatureSensor") == 0) {
1314 if (temp_list_add(temp_list, value)) {
1317 } else if (strcasecmp(key, "PressureOffset") == 0) {
1318 config_press_offset = atof(value);
1319 } else if (strcasecmp(key, "TemperatureOffset") == 0) {
1320 config_temp_offset = atof(value);
1329 * Shutdown callback.
1331 * Close I2C and delete all the buffers.
1333 * @return Zero when successful (at the moment the only possible outcome)
1335 static int collectd_barometer_shutdown(void) {
1336 DEBUG("barometer: collectd_barometer_shutdown");
1338 if (sensor_type == Sensor_MPL115) {
1339 averaging_delete(&pressure_averaging);
1340 averaging_delete(&temperature_averaging);
1342 temp_list_delete(&temp_list);
1345 if (i2c_bus_fd > 0) {
1348 sfree(config_device);
1355 * Plugin read callback for MPL115.
1357 * Dispatching will create values:
1358 * - <hostname>/barometer-mpl115/pressure-normalized
1359 * - <hostname>/barometer-mpl115/pressure-absolute
1360 * - <hostname>/barometer-mpl115/temperature
1362 * @return Zero when successful.
1364 static int MPL115_collectd_barometer_read(void) {
1367 double pressure = 0.0;
1368 double temperature = 0.0;
1369 double norm_pressure = 0.0;
1371 value_list_t vl = VALUE_LIST_INIT;
1374 DEBUG("barometer: MPL115_collectd_barometer_read");
1380 /* Rather than delaying init, we will intitialize during first read. This
1381 way at least we have a better chance to have the reference temperature
1382 already available. */
1383 if (!avg_initialized) {
1384 for (int i = 0; i < config_oversample - 1; ++i) {
1385 result = MPL115_read_averaged(&pressure, &temperature);
1387 ERROR("barometer: MPL115_collectd_barometer_read - mpl115 read, "
1388 "ignored during init");
1390 DEBUG("barometer: MPL115_collectd_barometer_read - init %d / %d", i + 1,
1391 config_oversample - 1);
1394 avg_initialized = 1;
1397 result = MPL115_read_averaged(&pressure, &temperature);
1401 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1403 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1404 sstrncpy(vl.plugin_instance, "mpl115", sizeof(vl.plugin_instance));
1409 /* dispatch normalized air pressure */
1410 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1411 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1412 values[0].gauge = norm_pressure;
1413 plugin_dispatch_values(&vl);
1415 /* dispatch absolute air pressure */
1416 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1417 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1418 values[0].gauge = pressure;
1419 plugin_dispatch_values(&vl);
1421 /* dispatch sensor temperature */
1422 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1423 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1424 values[0].gauge = temperature;
1425 plugin_dispatch_values(&vl);
1431 * Plugin read callback for MPL3115.
1433 * Dispatching will create values:
1434 * - <hostname>/barometer-mpl3115/pressure-normalized
1435 * - <hostname>/barometer-mpl3115/pressure-absolute
1436 * - <hostname>/barometer-mpl3115/temperature
1438 * @return Zero when successful.
1440 static int MPL3115_collectd_barometer_read(void) {
1443 double pressure = 0.0;
1444 double temperature = 0.0;
1445 double norm_pressure = 0.0;
1447 value_list_t vl = VALUE_LIST_INIT;
1450 DEBUG("barometer: MPL3115_collectd_barometer_read");
1456 result = MPL3115_read(&pressure, &temperature);
1460 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1462 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1463 sstrncpy(vl.plugin_instance, "mpl3115", sizeof(vl.plugin_instance));
1468 /* dispatch normalized air pressure */
1469 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1470 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1471 values[0].gauge = norm_pressure;
1472 plugin_dispatch_values(&vl);
1474 /* dispatch absolute air pressure */
1475 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1476 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1477 values[0].gauge = pressure;
1478 plugin_dispatch_values(&vl);
1480 /* dispatch sensor temperature */
1481 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1482 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1483 values[0].gauge = temperature;
1484 plugin_dispatch_values(&vl);
1490 * Plugin read callback for BMP085.
1492 * Dispatching will create values:
1493 * - <hostname>/barometer-bmp085/pressure-normalized
1494 * - <hostname>/barometer-bmp085/pressure-absolute
1495 * - <hostname>/barometer-bmp085/temperature
1497 * @return Zero when successful.
1499 static int BMP085_collectd_barometer_read(void) {
1502 double pressure = 0.0;
1503 double temperature = 0.0;
1504 double norm_pressure = 0.0;
1506 value_list_t vl = VALUE_LIST_INIT;
1509 DEBUG("barometer: BMP085_collectd_barometer_read");
1515 result = BMP085_read(&pressure, &temperature);
1519 norm_pressure = abs_to_mean_sea_level_pressure(pressure);
1521 sstrncpy(vl.plugin, "barometer", sizeof(vl.plugin));
1522 sstrncpy(vl.plugin_instance, "bmp085", sizeof(vl.plugin_instance));
1527 /* dispatch normalized air pressure */
1528 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1529 sstrncpy(vl.type_instance, "normalized", sizeof(vl.type_instance));
1530 values[0].gauge = norm_pressure;
1531 plugin_dispatch_values(&vl);
1533 /* dispatch absolute air pressure */
1534 sstrncpy(vl.type, "pressure", sizeof(vl.type));
1535 sstrncpy(vl.type_instance, "absolute", sizeof(vl.type_instance));
1536 values[0].gauge = pressure;
1537 plugin_dispatch_values(&vl);
1539 /* dispatch sensor temperature */
1540 sstrncpy(vl.type, "temperature", sizeof(vl.type));
1541 sstrncpy(vl.type_instance, "", sizeof(vl.type_instance));
1542 values[0].gauge = temperature;
1543 plugin_dispatch_values(&vl);
1549 * Initialization callback
1551 * Check config, initialize I2C bus access, conversion coefficients and
1555 * @return Zero when successful.
1557 static int collectd_barometer_init(void) {
1559 DEBUG("barometer: collectd_barometer_init");
1561 if (config_device == NULL) {
1562 ERROR("barometer: collectd_barometer_init I2C bus device not configured");
1566 if (config_normalize >= MSLP_INTERNATIONAL && isnan(config_altitude)) {
1567 ERROR("barometer: collectd_barometer_init no altitude configured "
1568 "for mean sea level pressure normalization.");
1572 if (config_normalize == MSLP_DEU_WETT && temp_list == NULL) {
1573 ERROR("barometer: collectd_barometer_init no temperature reference "
1574 "configured for mean sea level pressure normalization.");
1578 i2c_bus_fd = open(config_device, O_RDWR);
1579 if (i2c_bus_fd < 0) {
1580 ERROR("barometer: collectd_barometer_init problem opening I2C bus device "
1581 "\"%s\": %s (is loaded mod i2c-dev?)",
1582 config_device, STRERRNO);
1586 /* detect sensor type - this will also set slave address */
1587 sensor_type = detect_sensor_type();
1589 /* init correct sensor type */
1590 switch (sensor_type) {
1592 case Sensor_MPL3115: {
1593 MPL3115_adjust_oversampling();
1595 if (MPL3115_init_sensor())
1598 plugin_register_read("barometer", MPL3115_collectd_barometer_read);
1602 case Sensor_MPL115: {
1603 if (averaging_create(&pressure_averaging, config_oversample)) {
1605 "barometer: collectd_barometer_init pressure averaging init failed");
1609 if (averaging_create(&temperature_averaging, config_oversample)) {
1610 ERROR("barometer: collectd_barometer_init temperature averaging init "
1615 if (MPL115_read_coeffs() < 0)
1618 plugin_register_read("barometer", MPL115_collectd_barometer_read);
1622 case Sensor_BMP085: {
1623 BMP085_adjust_oversampling();
1625 if (BMP085_read_coeffs() < 0)
1628 plugin_register_read("barometer", BMP085_collectd_barometer_read);
1631 /* anything else -> error */
1633 ERROR("barometer: collectd_barometer_init - no supported sensor found");
1641 /* ------------------------ plugin register / entry point
1642 * ------------------------ */
1645 * Plugin "entry" - register all callback.
1648 void module_register(void) {
1649 plugin_register_config("barometer", collectd_barometer_config, config_keys,
1651 plugin_register_init("barometer", collectd_barometer_init);
1652 plugin_register_shutdown("barometer", collectd_barometer_shutdown);